Oil switch



J. C. RAH

lFeb. 21, 1933.

OI'L SWITCH Feb. 21, 1933. J Q RAH 7 1,898,744

oIL SWITCH Filed Feb. 6, 1932 5 Sheets-Sheet 2 fa/@2W 17059/2972 J. C.RAH

OIL SWITCH Feb. 21, 1933.

Filed Feb. 6, 1952 3 Sheets-Sheet 5 Patented Feb. 2l, 1933 STATES PATENTOFFEE JOSEPH C. RAH, OF CHICAGO, ILLINOIS, ASSIGNOR TO DELTA STARELECTRIC COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS OILSVITCH Application filed February This 'nvention relates to oil switchesand is particularly concerned with novel and improved features in oiland air break disconnect switches. Such switches are used forestablishing and for maintaining connections between different cables,such as between main lines and feeders, or between overhead andunderground lines. or combinations thereof, and for disconnecting theestablished connections when desired or necessary for the operation ofthe system.

Trouble and danger of various kind might occur during 'the maintenanceof such connections, as well as during the'connecting and disconnectingoperations of switches of this cha acteiz The principal aim of thisinvention resides in the provision of novel features and improvements ofsuch a nature as to furnish a commercially simple and technicallysatisfactory device, and thereby eliminating trouble and danger to theservice and to the maintenance force. The various objects accomplishedby the invention are briefly enumerated below:

One object resides in the provision of a simplified device containingstandardized parts and elements whereby it is made possible to connectoverhead lines or underground cables interchangeably to either side ofthe housing or container thereof. v

Another object relates to improved switch mechanisms disposed in theinterior of the housing or container and operable from the outside,whereby established connections can be successively interrupted at aplurality of points, namely, at a point disposed within the liquidinsulating medium, such as oil, and at a point disposed within an airspace.

A further obj ect is realized by the provision of means within thehousing or container and cooperating with the switch mechanism, wherebythe transmission of tension or voltage variations occurring along thesurface of the liquid insulating medium, to the lines, is entirelyavoided.

Still another object resides in improved contact mechanisms furnishing apositive and reliable operation with a minimum amount of wear.

Other objects and features will appear as the detailed descriptionprogresses which is rendered below with reference to the accompanyingdrawings.

In these drawings Fig. l represents a sectional side elevation through adevice embodying the novel and improved features intimated above. Thesection is taken through the housing approximately on lines 1-1indicated in Fig. 2, and shows certain parts in cross section and othersin elevation;

Fig. 2 is a sectional side elevation taken thro gh the housingapproximately on lines 2-2 in Fig. 1, also showing parts in crosssection and in elevation, respectively, and

Figs. 3 to 7, inclusive, illustrate improved Contact mechanisms.

Like reference numerals applied in the Figs. 1 and 2 indicate likeelements and parts. Unessential details have been omitted for the sakeof a clear and comprehensive description.

The device comprises essentially a container or housing l0, preferablymade of metal, and provided with il nges 11 which may he welded thereto.A top portion 12 is secured to the housing by means of flanges 13 whichregister with the flanges 11 as shown. Gaskets may be intel-poseebetween the flanges if desired. VEhe attachine-nt maj,lv be accompli..Aby nie-ans of rc movable bolts such as 14. It will be observed that theflanges 13 of the top portion, secured to the sides thereto, projectlaterally into the container as is particularly apparent from Fig. 2,the projecting portions heing indicated by the numeral 15. Secured tothose projecting` flange portions inside the container are certainmechanisms which will l .y ntly be described in d The top portion 12 isprovided with tuo opnositely disposed openings or apertp-QS of the sainesize and shape Fig. l at G and 17. The dov'invr stablish plurality of cocables or lines and th c, .il

i' side, and the abo s tion-d ononare conveniently situated so toporniit the entry and eXit of the respective con nections. A cover box1S is mounted on thel right side of the device shown in Fig. 1, coveringthe opening 17. This cover box 18 is secured to the top portion 12 ofthe container by means of bolts such as 19 and 20, and attached thereto,by means of bolts 21 and 22, is the connect-ing sleeve 23. lt isunderstood that gaskets may be employer wherever it is desired ornecessary. A cable such as the cable 24 enters into the device throughthe sleeve 23. Other cables entering at this side of the device areconnected through similar connecting sleeves mounted on the cover box18. Secured to the other side of the top portion 12 and covering theopening 16 therein, is a side cover 25, being attached by means Vofremovable bolts such as 26 Vand 27. lnsulators such as 28 and 29carrying certain terminals are mounted laterally in cooperation with thecover 25, as shown.

The connections between the corresponding cables and lines areestablished by means of switch mechanisms disposed within the containerand operable from the outside. rlhe structure and operation of thesemechanisms will be presently explained. Howeier, attention may be calledat this point to the simplicity of construction of the entrance and exitof the various lines and cables. rlhe openings in the top portion 12 ofthe housing or container are or" substantially identical dimensions andshapes. The covers 18 and 25 are interchangeable, and either of thecovers can, therefore, be secured to either side of the top portion 12.The various parts and elements of the switch mechanism may bestandardized and may be used on either side of the container or housing.Hence, my invention provides a simple device, comprising standardized,interchangeable parts, which may be readily attached or removed andexchanged, depending upon the particular location and the character ofthe cables and lines entering and leaving the device, respecti ely.

The housing or container is provided with insulating walls such asindicated at 90 to 93, inclusive, cooperating with an insulatlj j base94. A lid 30 is suitably secured to the. top port-ion 12 covering theopening 31 thereon. rlhe attachment of this lid may be accomplished bymeans of suitable bolts or the like.

The manner in which certain. connectors, switch terminals, and thecorresponding cable and line connections are provided within thecontainer will be described next, particularly with reference to Figures1 and 2. lt may be mentioned at this point that the device is designedfor a plurality of connections, accoinmodating, in the exam leillustrated, three sets of connections each be' g connected throughcertain switching equipment.

Secured' to the flange portions 15 projecting laterally into thecontainer are the mem-- bers 32 and 33. Only portions of the liangemember 15 and the mounting member 33 are shown in Figure 1 in order tokeep the drawings clear and simple. The members 32 and 33 hold amounting plate 34 extending transversely across the container insidethereof as is apparent from Fig. 2. Sleeves such as 35, 36 and 37, onefor each connection are carried by the plate 34. The sleeve 36 is shownslightly shorter in Figure 1 than in Figure 2 in order to illustrateother parts more clearly. The insulators 88, 39 and 40, one for eachconnection, extend through the sleeves 35, 36 and 37, respectively, andare firmly secured thereto by cementing as is indicated in Fig. 1 by thereference numeral 41 showing how the insulator 39 extends through thesleeve 36 and how it is cement-ed thereto. A connector extends througheach insulator, projecting from the top thereof, in the form of athreaded lug such as indicated at 42, 43 and 44, respectively. Theterminals 45, 46 and 47 of the cables are fastened to the correspondingconnector lugs by means of nuts such as 48, 49 and 50, respectively, asshown. Nuts such as 51, 52 and 53, hold the connectors in assembly withthe corresponding insulators. Secured to the other end of each of theinsulators, in contact with the corresponding connector therein, is ayieldable spring leaf contact, such as shown at 54, 55 and 56, themounting thereof in conductive relation with the connector beingaccomplished by means of a suitable bolt or nut such as indicated at 57,58 and 59. It will be seen that these yieldable contacts are reinforcedby leaf springs in order to secure the required mechanical strength andflexibility and thereby securing reliable operation. Y

T he foregoing description shows that each of the various cables, suchas the cable 24, enters through a wiping sleeve such as 23 on one sideof the device (the sleeves being mounted on the cover box such as shownat 18)V and that each cable is attached to a connector extending throughan insulator such as 39 and terminating in the yieldable contact such as55.

The above completes the description of the manner in which the entry ofthe various cables into the` device is efected. lt is understood, ofcourse, that I employ the termS-entry or exit-or equivalent language,only for the salie of description and not for the purpose of limitation.The entry or exit of cables or lines will be determined by the use ofthe device, and, since my invention provides for utmost standardizationand interchangeability, it is apparent that this interchangeability willalso affect the terminology to be employed. Vhat might be properlytermed the-entry-of the cable or line in one case, may be referred toas-exit in another case.

The description will be now continued with particular reference toFig. 1. This ligure shows only the operating mechanisms and variousother parts belonging to one set of connections. It will be recalled,however, that the device contains three such connections as is indicatedin Fig. 2. Insulating partitions may be provided between the sets ofconnections if desired. The manner in which a cable enters into thedevice, and in which it is secured to a connector terminating in ayieldable or flexible contact, has been explained. The provisions forthe exit of the cables or lines will be described next.

Secured to the cover 25 shown on the left side of the device in Fig. 1,are insulators such as 28 and 29, one being disposed within the deviceand the other projecting therefrom. A connector extends through theseinsulators and terminates within the device in a terminal lug projectingfrom the insulator 28 as shown at 61. Attached to this terminal lug bymeans of bolts such as 62 and 63, and depending therefrom, is aconnector link 64. The switch contact 65 projects into this link and isslidable therein, as will be presently described. The lines or cablessuch as extend from the device as shown, and each is connected to acorresponding feeder or line cable provided in the system.

The switch mechanism set for establishing the connection between a.cable such as 24 and a line or cable such as 60 comprises elements orparts which are best illustrated in Fig. 1. It should be borne in mindin reading the following description, that the mechanism accomplishes anumber of objects, namely, the provision of means, effective during themaintenance of a connection, for eliminating variations or fluctuationsof voltage occurring along the surface of the liquid insulating mediumcontained in the device; -the provision of novel and simplifiedoperating means for breaking such a connection successively at aplurality of points, i. e., at a point within the liquid insulatingmedium and then at a point disposed within an air space; and theprovision of simplified and improved means for effectively and reliablyoperating the mechanism from the outside. The structure of the set ofswitch mechanism shown in Figure 1 is described below.

' bers 66-67 and the bar 68 may be made of suitable Wood. Contacts suchas 71, 72 and 73, one for each set of mechanism, are secured to the bar68. It will be observed that a lever is integral with each Contact andprojects therefrom as is indicated in Fig. l at 74, and that this leverconnects with a link system comprising the links such as 75 and 76 andthe lower link portion 77 of the movable Contact rod 65, which slideswithin an opening of the terminal link 64. The connection between thecable 24 and the line 60 is thus maintained through the connectorextending through the insulator 39, contacts 55, 7 1 7 4, link 77,contact rod 65, link 64, terminal lug 6l, line or cable 60.

Assuming now that the lever contact 71-74, which is mounted on thetransverse bar 68, is moved in an anti-clockwise direction, it will beseen, that the connection is broken first between the contact 71 and theyieldable contact 55, and, if the anti-clockwise movement is continued,the Contact will be moved downwardly and will slide out of engagementwith the link 64. The contacts 55 and 71 are immersed in a suitableliquid insulating medium such as oil, the oil level being indicated bythe reference numeral 78. The terminal contact link 64 cooperating withthe movable contact 65 is disposed above the oil level. Accordingly, ifsuch anti-clockwise movement of the Contact lever 71-74 occurs, theconnection between the contact 55 and the terminal contact 64 will bebroken, first by the disengagement of the contact 71, within theinsulating oil, and then by the disengagement of the movable contact rod65 from the terminal Contact 64 within the air space above the oillevel.

The link members 75 and 76 may be made of insulating material. It willbe understood, of course, that the switch mechanism just described isindividual to a set of connections. The transverse bar 68 is common toall sets and carries the lever contacts such as 71-74. The manner inwhich the anticlockwise motion of the lever contacts 71-74 is effectedis as follows An operating shaft 80, clearly shown in Figure 2, ismounted on the top portion 12 of the housing by means of a suitablebracket 81 and bushing 83, so that the shaft projects from the housingand may be operated by means of its square end 82. A packing gland maybe inserted in the bushing 83, and a suitable sleeve nut 84 may beemployed for completing the assembly. The shaft 80, extending into thetop portion l2 of the housing, is adapted to actuate a toggle jointcomprising the members 85 and 86. The latter connect with an angularlever 87 keyed to the shaft 88 extending transversely across the topportion l2 of the housing, as is particularly shown in Fig. 2. The shaft88 may be mounted at its ends in suitable bearings or brackets such as89.

When the shaft 80 is actuated by means of a crank or key or the like,turning in clockwise direction (as shown in Fig. 1) ,the toggle link 85will move downwardly, thereby actuating he toggle link 8G andV throwingthe angular lever 87 in anti-clockwise direction, rocking the shaft 88.Keyed to this shaft are levers, such as 87 '-99 which are linked withthe downwardly extending links such as 76A at point99 indicated inFigure 2 in the form of a short shaft. Accordingly', Vwhen the shaft 88is rocked as above explained,l the levers such Vas 87 will move thelinks such as 7 6 downwardly, thereby actuating the link systenis formoving the contacts such as f1 out of engagement with the correspondingyieldable contacts such as 55, and thereby moving the contact rods in aperpendicular1 motion parallel to the links 76, so as to break theconnection between the contact rods 65 and the terminal links 6st withinthe air space above the oil level. T he interruption of theconnections'is successive, first at contacts 55-71 within the insulatingoil contained in the device and then at 65-64 within the air space abovethe oil level. Plugs for inserting oil into ythe container and drainplugs may be provided. I have not shownv such plugs because they arewell known and do not affect the invention.

lt is believed that the foregoing description discloses the operatingmechanism with sutcient clarity so that a correct understanding may beobtained. rllhe means for eliminating the transmission of voltageflucbers arranged like spokes( radiating from the inside wall of theinsulating sleeve 95 and attaching to the corresponding contact rod 55,as is indicated by the numerals 96, 97, 98 and 99. The insulatingsleeves may be suitably dimensioned according to the effect whic i itisdesired t-o achieve. rlhey can. be readily exchanged by pulling thecontact rods 65 out of engagement with the terminal linkslilV and bysliding the sleeves 95 from the Contact rods 65, and if desiredreplacing the same in a like manner with insulating sleeves of differentdimensions. rEhe insulating sleeves 95 move with the contact rods 65 upor down upon the establishing of the connections or upon breaking theconnections, respectively. During the operation ofthe device, that is,during the time the connections are maintained, the insullating sleeves95 will be positioned similar-V lly as is shown in Fig. 1. ln otherwords, the insulating sleeves are interposed between the surface of theinsulating oil and the contact rods 65, while the connections aremaintained. Accordingly, the contact rods such as 65 will transmit tothe terminal links such as 64 and, therefore, to the lines or cables su'li as 60, the potential obtaining within the insulating oilirrespective of the potential fluctuations occurring along the surfacetl ereof. lt will be appreciated that the function of the insulatingsleeve is eX- tremly important in view of the fact that creepingvoltages always occur along the surface of the insulating oil whichalter the voltage on the lines or cables. The insulating sleeve whenproperly proportioned does not merely reduce the voltage fluctuations,but actually eliminates the same.

ln Figs. 3 to 7, inclusive, l have shown several embodiments of contactswhich mayA be Vused advantageously in connection with oil switches ingeneral and likewise with si 'tches of the character described in thisspecification.

The contact arrangement shown in Fig. 3

consists of a kidney shaped yieldable contact design-ated by the numeral100 and a yieldable spring leaf contact 101. A. movable contact 102 ismounted on a squared shaft 103 and is provided with a lever projection104 maintaining engagement with the leaf spring 101. The contacts 100and 101 are in engagement with ronnectors disposed in the insulatorssuch as 105 and 106, respectively, extending into the liquid insulatingmedium. rllhe movable contacts 102 and 104-L may be operated by means ofthe link lever 10'? actuating the member 108.

vWhen the lever 107, and with it the member 108, are operateddownwardly, the contacts 10Q-104s will move in anti-clockwise directionuntil the connection is broken between the contact 104 and the yieldablecontact 101. The contact 102 always maintains connection with theyieldably kidney shaped contact 100.

Figs. l and 5 show an embodiment which s in principle similar to theembodiment hown in Fig. 3. There is, however, a diference the provisionof a contact member 09 which is removably secured to the contact lever105i by screw means such as 110. liepeated operation of this contactarrangementcauses on the contact 104 and on the contact member 109,respectively, due to the arcing occurring between the contact 109 andthe leaf spring contact such as 101. rilhe contact member 109 isremovable and, therefore, it can be exchanged damaged by arcing. insteadof providing a kidney shaped contact as shown in Fig. 3 there isprovided a U-shaped contact 111. Ar-

ranged slidably within the depending legs of this contact is the contact112 being integral with the contact lever 104 and mounted on a'squareshaft such as 103. The structure is in other respects similar to the onedescribed in connection with the embodiment shown in Fig. 3, except thatI employ a push rod such as 113 pivotally mounted at 114 on the contactlever 104. The contact members 101 and 111 are mounted in conductiveengagement with corresponding connectors disposed within insulators105-106.

The embodiment shown in Fig. 6 shows a further development of thecontact arrangement along the lines of the contact arrangement shown inFigs. 4 and 5. The difference of this arrangement with regard to thepreviously described embodiments resides in the use of a U-shapedcontact 115 in place of a yieldable contact such as 101 and 101 shown inthe other embodiments. A contact 116 on a contact lever 117 operateswithin the legs of the U-shaped contact 115 in the same manner as thecontact 112 operates within the legs of the U-shaped Contact 111. Themounting of the movable contacts on a square carrier shaft and theoperation of these contacts, is substantially the same as the onedescribed previously.

In Fig. 7 is shown a movable contact arrangement having a body 118clamped around a rotatable carrier shaft 119. At the ends of the arms ofthis movable contact body are mounted the contacts 120 and 121 by meansof bolts 122 and 123, respectively. Either of these contacts 120 and 121is removable from the arms of the contact body 118. The contact 121engages the yieldable arcuate contact spring 124 which is mounted inconductive engagement with a connector disposed within the insulator125, and the yieldable spring leaf contact 126 is mounted in conductiveengagement with a connector disposed within the insulator 127. Theoperation of the contacts is achieved by means of rocking the shaft 119and thereby moving the contact 121 over the yieldable arcuate contact124 and operating the contact 120 out of engagement or into engagementwith the spring leaf contact 126.

It will be realized that the structure shown in Figures 1 and 2 includesmany novel features which will be appreciated by those experienced inthe art. The contacts shown in the Figures 3 to 7. inclusive, alsodisclose simplified and highly efficient contact arrangements presentingfeatures of advantages with simplified structures. Changes may bedevised in details of the structure of the several elements and partsand in the form and manner in which they are assembled. It is thereforeto be understood that I have shown specic structures in order to showembodiments of mv invention for the purpose of guiding others inrealizing the same in practice, but not for indicating its structural orfunctional limitations. What I believe is new is pointed out in theappended claims.

I claim as my invention:

1. A combined oil and air break disconnect switch comprising a housingcontaining an insulating medium, a pair of conductors entering saidhousing, a pair of connector means disposed on the same level onopposite sides of said housing for receiving said conductors. terminalmeans connected to each of said connectors, one of said terminal meansbeing disposed within said medium and the other being disposed above thelevel of said medium within said housing, a movable contact slidablydisposed within the terminal above said level of said medium, a movablecontact engaging said terminal within said medium, link means forsimultaneously moving said contacts, and operating means projecting fromsaid housing for actuating said link means to move said contactssuccessively out of engagement with said terminal means.

2. An oil and air break disconnect switch, comprising, in combination, ahousing containing insulating oil, a pair of conductors entering saidhousing on the same level from opposite sides thereof, a pair ofconnector means, one connected to each of said conductors within saidhousing, one of said connector means extending into said insulating oiland the other disposed above the level of the same, removable contactmeans cooperating with each of said connector means for maintainingconnection between said connectors, means for moving the contact meanswithin said insulating oil out of engagement with the connector therein,and lever means extending from said contact means for moving saidcontact means above said oil level out of engagement with the connectorthereat.

3. In an oil switch, a first terminal immersed in insulating oil, asecond terminal disposed above the level of said oil, a rotatablecontact cooperating with said irst terminal, a slidable contactcooperating with said second terminal, a lever integral with said firstcontact movably engaging said second contact for maintaining conductiverelation therebetween, a toggle oint, link means connecting said togglejoint with said lever, and means projecting laterally from said switchfor actuating said toggle joint to move said link for operating saidlever to disengage said rotatable Contact from said first terminalwithin said oil and to disengage said slidable contact from said secondterminal above said oil level.

4. A switch of the class described, comprising, in combination, acontainer consisting of a lower housing portion for receiving a liquidinsulating medium, an upper housing portion for inverted attachment tosaid lower portion, two apertures of substantially the same dimensionsprovided on opposite sides in said upper portion on the same level,

cover means for interchangeable attachment to said upper portion forclosing said apertures, means in each cover for introducing a conductorinto said upper portion el' said switch, terminal means secured to eachot said conductors within said switch and disposed coaxial therewith andradially spaced lfrom each other, one of said terminals extending intoand being immersed in said inediui 'and the other termina-l disposedabove the level thereof, a contact projecting through the level or" saidmedium into the terminal above said level and being slidable therein, arotatable contact cooperating with the terminal immersed in said medium,means for actuating said contacts to break an established connection bysuccessively disengaging said rotatable contact and then said slidablecontact from said terminals, and means on said slidable contact formaintaining thereon the potential obtaining on said immersed contactregardless of potential variations along the level of said medium. v

5. ln an oil switch ofthe class described, a boX containing insulatingoil, a lirst stationary terminal contact immersed in said Oil, a secondstationary terminal contact disposed above the level of said oil, arotatable contact cooperating with said first contact, a contact rodprojecting through the level of said oil into said second stationarycontact and slidably rdisposed therein, link means immersed in said oilfor actuating said rotatable contact to disengage said rst contact,means on said rotatable Contact and on said link means for actuatingsaid contact rod to slide out-ot engagement with said second stationaryContact, and removable insulating means carried by said slidable contactrod for transmitting to said second stationary terminal contact disposedabove said oil level solely the potential obtaining on said immersedstationary contact terminal when the connection is maintained betweensaid terminals.

6. ln an oil switch of the class described having a terminal immersed inoil and a terminal disposed above theoil level, a movable contactcooperating with said immersed terminal, a movable Contact cooperatingwith said other terminal, means for actuating said contacts to interruptthe connection between said terminals, and removable and exchangeableinsulatin c' means of predetermined properties associated with themovable contact cooperating with said other terminal `for insulatingsaid contact against the variable potential obtaining along said oillevel during the maintenance of a connection between said terminals.

7. In an oil switch of the class described having a terminal immersed'inoil and a terminal within an air space above the oil level, a contactrod slidably engaging said latter terminal and extending through theroil level into movable conductive engagement with said first immersedterminal,rtlie potential obtaining on said immersed terminal beingtransmitted to said air terminal by means otsaid Contact rod, and atubular insulatingy member .removably secured to and spaced Jfrom saidcontact rod for eliminating the transmission of variable voltageuctuations on the surface ci said oil.

8. ln an oil switch of the class described having a terminal immersed inoil and a terminal within an air space above the oil level, a contactrod slidably engaging said latter terminal and extending through the oillevel into movable conductive engagement with said first immersedterminal, the potential obtaining on said immersed terminal beingtransmitted to said air terminal by means or" said contact rod, atubular insulating sleeve removably secured to and spaced from saidContact rod immediately above and below he oil level for insulating saidcontact rod against variable creeping voltages on the surface of saidoil'while a connection is maintained between said terminals, link meansfor actuating said contact rod, and means operable from the outside toractuating said link means to move said contact rod for successivelyinterrupting said connection first at said immersed terminal and then,at said air terminal above said oil level.

9. ln an oil switch of the class described having a terminal immersed inoil and a terminal within an air space above the oil level, a contactrod slidably engaging said latter terminal and extending through the oillevel into movable conductive engagement with said lirst immersedterminal, the potential obtaining on said immersed terminal beingtransmitted to said air terminal by means of said contact rod, a tubularinsulating sleeve removably secured to said contact rod and spacedtherefrom at a point immediately above and below said oil level forinsulating said contact rod against variable potential fluctuationsalong the surface of said oil while a connection is maintained betweensaid terminals, link means Jfor actuating said contact rod, toggle meansfory operating said link ineans,`and means for actuating said togglemeans from the outside to operate said link means for moving saidcontact rod to eliect an interruption of said connection successively atsaid immersed terminal and then at said terminal within said air spaceabove said oil level.

10. A switch deviceor1 the class described, comprising a containerhaving a bottom portion Vand a top portion joined by anges and forming ahousing, certain of said flanges projecting laterally into said housing,mounting means supported by said projecting flanges within said housing,a plurality or" insulators carried by said mounting means, connectorsdisposed within said insulators, conductors secured to said connectorswithin said top portion and terminal contacts secured thereto withinsaid lower portion of said housing, a common rotatable shafttransversely disposed within said bottom portion of said housing andcarried by said mounting means, switch contacts movably supported bysaid shaft for establishing engagement with said terminal contacts ofsaid connectors within said bottom portion, a rotatable common operatingshaft extending transversely across said top portion of said housing,links secured to said shaft for actuating said switch contacts, contactrods movably cooperating with said switch contacts and projecting fromsaid bottom portion into said top portion of said housing, stationaryterminals cooperating with said contact rods within said top portion ofsaid housing and conductors connected to said stationary terminals, andtoggle means for rocking said transverse shaft within said top portionto actuate said links for operating said switch contacts mounted on saidrotatable transverse shaft within the bottom portion and to move saidrod contacts to interrupt the connections between said switch contactsand said terminal contacts within said bottom portion and between saidcontact rods and said stationary terminals within said top portion ofsaid housing.

11. In an oil switch of the class described, comprising a containerpartially filled with insulating oil, a connector in said containerextending into said oil, a cable connected to said connector, a secondconnector disposed within said container above the level of said oil, aline connected to said second connector, switching means within saidcontainer for establishing a connection from said cable to said line,there being potential fluctuations along the surface of said oil levelduring the transmission of current over said established connection, andmeans associated with said switching means within said container forpreventing the transmission of said potential fluctuations to said line.

l2. In a device of the class described, comprising a container partiallyfilled with a liquid insulating medium, a connector in said containerdisposed so as to project therein from said medium to the upper portionof said container, a first conductor laterally entering the upperportion of said container and connected to said connector, a secondconnector laterally disposed within said upper portion of said containerabove the level of said medium, a second conductor connected to saidsecond connector, said first and second conductors entering said deviceat substantially the same level, switching means within said containerfor establishing a connection between said conductors, there beingpotential variations along the surface of said medium in said containerduring the transmission of current over said established con- JOSEPH C.RAH.

